what causes code po171

Question

What causes a PO 171 code  and a PO300 code in a 2001 Buiuc century and how do I fix them

Answer 1

There are several things that can cause the P0171 code, but probably the most common one is an intake air leak. Some common areas of leaks on that engine are the PCV hose, evaporative system purge solenoid valve, or upper intake manifold gaskets